Open end wrench



Feb. 18, 1941.

P. s. MORGAN OPEN END WRENCH Filed Nov. 19,1958

2 Sheets-Sheet 1 NN Q x M. a H 0 M Y m i. Mk 0 i? MRM Feb. 18, 1941. s, GA 2,232,259

OPEN END WRENCH Filed Nov. 19, 1938 2 Sheets-Sheet 2 IIIIIIHIIIHHMIIIII 'ATT RNEY Patented Feb. 18, 1941 UNITED STATES PATENT OFFICE OPEN END WRENCH Application November 19, 1938, Serial No. 241,295

8 Claims.

This invention relates to an open end wrench and more particularly to a wrench capable of obtaining a powerful grip on a nut or other object but easily and quickly released from the object.

Various attempts have been made heretofore to provide wrenches in which the handle is moved relative to the head of the wrench to efiect a tightening of the jaws. In practice, however, such wrenches have usually proved to be entirely impractical, or they have been too complicated to be suitable for use by the ordinary mechanic.

One object of my invention is to provide a practical wrench capable of gripping a nut or other object between its jaws with tremendous force, which is easily and naturally applied and regulated merely by movement of the handle after the preliminary adjustment of the jaws.

It is also an object of my invention to provide a simple, compact practical wrench having the foregoing properties and which is also capable of ratcheting about a nut to obtain a fresh grip on the nut.

Another object of this invention is to provide a practical wrench capable of ratcheting about a nut or other object when the handle is moved in one direction, and capable of locking the jaws in a powerful grip on the object when the handle is moved in the opposite direction.

Other objects and advantages of this invention will be apparent from a description of one embodiment thereof illustrated in the drawings, in which Figure 1 is a plan view of a wrench with the handle in an intermediate or neutral position.

Figure 2 is a side elevation of the wrench shown in Fig. 1.

Figure 3 is a vertical sectional view through the handle of the wrench, showing the head of the wrench in elevation and taken on the line 3-3 of Fig. 1.

Figure 4 is a horizontal sectional view on a larger scale through approximately the center of the wrench showing the movable jaw, adjusting knob and handle in elevation and in a position for tightening a nut.

Figure 5 is a View similar to Fig. 4 but showing the adjusting knob in section and the parts of the Wrench in the position occupied as the wrench is ratcheted about a nut to obtain a fresh grip thereon.

In the drawings, numeral It indicates a fixed jaw member adapted to cooperate with a relatively movable jaw member l I *for gripping a nut 2. The fixed jaw member ID is provided with a generally cylindrical opening l2a extending in a direction at right angles to the gripping surfaces l3 of the jaws and arranged to receive in sliding engagement the rack l4 provided with suitable teeth I5. One or both of the gripping surfaces 13 may be provided with suitable teeth as desired. The jaw portion of the movable jaw member H is integrally connected to the rack M by a centrally located flange l6 which is arranged to fit into the slot I! located centrally of the fixed jaw member, when the two jaw members are completely closed. Fixed jaw member ID is also provided with a window-shaped opening l8 overlapping the opening |2a and adapted to receive the knurled knob 19 which is provided with threads 20 to engage the teeth IE on rack M. The opening l8 may have its edges beveled so that the knob I9 may be more easily grasped and rotated. Knurled adjusting knob l9 has a pin 2| fixed thereto so that the knob may be moved in an axial direction and will be guided by the pin 2| sliding in the opening 22 in fixed jaw member l0. Interposed between the ledge 23 of the window-shaped opening I8 and the top of the knurled knob I9 is a circular spring washer member 24 that is arcuate in elevation to space the knurled knob l9 resiliently from the ledge 23 in a normal adjusted position.

The handle 25, which may be of any suitable shape, is pivotally secured to the fixed jaw member ID by the pin 26'. The inner end of handle 25 is provided with a cam surface 21 for engagement with the conical surface 28 on the bottom of the knurled knob l9. This cam surface 21 on the inner end of the handle 25 is cut away as at 21c and a toe portion 29 is provided to engage one end of the spring 30, preferably composed of a number of leaf springs attached to the fixed jaw member ID by means of the screw 3|. 40 An overlying rigid guard member 32 limits the effect of springs 39 and may also be held in place clamped over the springs 30 by the screw 3|.

In operation, the knurled knob 19 in the neu tral position of the handle shown in Fig. 1 may 45 be freely rotated to close or open the two jaw members It) and l I. For example, the jaw members may be tightened so that the jaws engage nut I2 more or less firmly, as illustrated in Fig.

l. The handle 25 is then moved in a clockwise 5o direction to the position shown in Fig. 4. As the handle is thus moved, the cam surface 21 on the inner end of the handle engages and wedges against the conical surface 28 at the lower end of the knurled knob 19, forcing the knurled knob l9 and with it the movable jaw member ll upward toward the fixed jaw member It]. By disposing the conical surface 28 so that it is substantially tangent to a circle described about the pin 26 and by properly designing the cam surface 21 with a sufficiently small angle, a tremendous lifting efiect on the knurled knob l9 and movable jaw member Il may be obtained. The jaws may thus be wedged and locked tightly together against the object to be moved, whether this object is small or large. During this wedging action of cam surface 21, the washer spring member 24 is compressed between the knurled knob l9 and ledge 23. I have found that as the jaws are tightened on a nut to be moved, th'is nut exerts a very strong opening reaction on the jaws, and that this opening reaction is stronger with smaller nuts. A mutilated nut may also be so shaped as to exert an unusually large opening effect on the wrench jaws. To avoid any movement of the handle 25 about pin 26 due to this opening reaction, I prefer to design the cam surface 21 so that as the jaws are wedged together, the leverage of cam surface 21 against the conical surface 28 is gradually increased until a locking point is finally reached. The opening reaction thus does not tend to rotate handle 25 to open the jaws after this locking point is reached because of the extremely small angle between this portion of cam surface 21 and surface 28.

After turning the nut l2 as far as possible, it is necessary to obtain a fresh grip on the nut in another position. For this purpose the handle is moved in the direction indicated by the arrow in Fig. 5. Cam surface 21 is brought clear of the conical surface 28 and due to the cutaway portion 2111, the knurled knob 19 is allowed to drop rapidly down to the position shown in Fig. 5, moving the movable jaw member I! down a corresponding distance and allowing the gripping surfaces l3 to slide around on the nut to a new position. As the handle is turned in this counter clockwise direction, the toe 29 engages and moves the springs 3!]. Springs 30 thus tend to turn the handle in a clockwise direction with respect to the fixed jaw member until the springs 30 contact the guard member 32, at which time the handle has been brought back to the neutral position of Fig. 1. As soon as the jaws have been slid around on the nut to a position permitting the jaws to close, the springs 30 tend to raise the knurled knob l9 and movable jaw member II by a quick lifting prying action. The handle may then be positively moved in a clockwise direction bringing the cam surface 2'! again into operation and the nut I2 is again firmly grasp-ed between the jaws of the Wrench as previously described.

The spring washer member 24 resiliently spaces the knurled knob I 9 from the ledge 23 on the fixed jaw member Hi and the amount of this spacing should be proportioned in accordance with the particular design of the cam surface 21. The guard 32 should be adjusted to such a position that the inner end of the handle 25 is not pressed tightly against the surface 28 of knurled knob I9 by the force of springs 38 acting against spring member 24. This adjustment permits the handle to remain in a neutral position in which the knurled knob is free from undue frictional engagement and may be easily rotated to adjust the jaws in the ordinary manner.

The teeth provided on the jaw gripping sur faces 13 have been found to prevent mutilation of a nut in the use of a wrench in accordance with my invention. Where teeth are provided on the jaws of an ordinary wrench or on the jaws of a self-tightening wrench having insufiicient leverage, there is a distinct tendency for the teeth to tear and mutilate the nut due to slippage. The teeth in my wrench, however, are afforded such a tight grip on a nut before a strong turning force is exerted on the nut that even stubborn nuts are not mutilated at the corners or torn by the teeth.

It will thus be seen that I have provided a simple and practical wrench having a tremendous gripping power when applied to a nut and also having the ability to ratchet about a nut when the handle is merely moved back and forth by a mechanic. The wrench may be easily operated with one hand and it is unnecessary to hold the head of the wrench in one hand While the handle is adjusted by the other hand to a suitable position. This wrench is also sturdy enough to be hammered and otherwise treated roughly as is frequently necessary in the normal use of wrenches.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

1. An open end wrench comprising a fixed jaw member, a movable jaw member, a rotary adjusting member having threads for adjusting the position of said movable jaw, said adjusting member being supported by said fixed jaw member for movement in an axial direction and having a conical lower surface, resilient means for opposing movement of said adjusting means for only a portion of its path of movement toward said fixed jaw member, and a handle pivotally secured to said fixed jaw member having a cam surface for acting on said lower surface to force said adjusting member and said movable jaw member toward said fixed jaw member.

2. An open end wrench comprising a fixed jaw member, a movable jaw member, a rotary adjusting member having threads for adjusting the position of said movable jaw, said adjusting member being supported by said fixed jaw member for movement in an axial direction, resilient means for opposing movement of said adjusting means for only a portion of its path of movement toward said fixed jaw member, and a handle pivotally secured to said fixed jaw member having an end surface shaped to allow said jaw members to open sufficiently to permit ratcheting when the handle is moved in one direction and shaped to wedge said jaw members towards each other against the resistance of said resilient means when the handle is moved in the opposite direction.

3. An open end wrench as defined in claim 2 including spring means for urging said handle in a direction to wedge the jaw members towards each other, said spring means and the resilient means having only a limited effect to permit easy rotation of the adjusting member.

4. An open end ratcheting wrench comprising a fixed jaw member, a movable jaw member, a handle pivotally secured to the fixed jaw member, a rotary member having threads for adjusting said movable jaw member and arranged for axial movement to open or close said jaws, means resiliently spacing said rotary member from said fixed jaw member, a bearing surface associated with the lower portion of said rotary member disposed substantially normal to a radius extending from said handle pivot when said rotary member is in a position to hold the jaws in the closed position, and a cam surface on the inner end of said handle for cooperating with said bearing surface to wedge said jaw members together against the resistance of said spacing means, said cam surface being cut away to permit opening of said jaws when said handle is moved to withdraw said cam surface from engagement with said bearing surface.

5. A wrench as defined in claim 4 including a spring urging the cam surface towards engagement with the bearing surface and means preventing said spring from holding said surfaces,

in tight engagement with each other.

6. A ratcheting wrench comprising a fixed jaw member, a movable jaw member, a rotary member for adjusting the relative positions of said jaw members and movable in an axial direction to open and close said members, a handle pivotally secured to said fixed jaw member, a bearing surface associated with the lower portion of said rotary member disposed substantially normal to a radius from said handle pivot when said rotary member is in a position to hold said jaw members closed, a surface on the inner end of said handle for cooperating with said bearing surface shaped to exert a prying action thereon to move the jaw members into substantially closed position, and a camming surface on the inner end of said handle acting on said bearing surface to Wedge the jaw members together and lock them against an object therebetween.

7. A ratcheting wrench comprising a fixed jaw member, a movable jaw member, a rotary member for adjusting the position of said movable jaw member relative to said fixed jaw member, said rotary member having a conical bearing surface and being movable in an axial direction to allow said jaw members to open, and a handle pivotally secured to said fiXed jaw member having a cam surface acting on said conical surface when the handle is moved in one direction to wedge said jaw members together and having a cut away prying surface allowing said jaw members to open for ratcheting about a nut when the handle is moved in the opposite direction, said bearing surface being substantially tangent -to a radius from said handle pivot when said jaw and rotary members'are in the closed position.

8. A ratcheting wrench comprising a fixed jaw member, a movable jaw member, a rotary member for adjusting the position of said movable jaw member relative to said fixed jaw member,

'said rotary member being movable in an axial direction to allow said jaw members to open and having a bearing surface associated therewith, a handle pivotally secure-d to said fixed jaw member having a cam surface acting on said bearing surface when the handle is moved in one direction to wedge said jaw members together and having a cut away prying surface allowing said jaw members to open for ratcheting about a nut when the handle is moved in the opposite direction, spring means urging said handle in a direction to close the jaw members, and means limiting the effect of said spring means to allow easy rotation of said rotary adjusting member.

PORTER S. MORGAN. 

